Mold for molding articles composed of different materials

ABSTRACT

A mold has at least one mold cavity and two mutually isolated sprues. Each sprue is connected via a different runner or gate to the mold cavity. A different material is fed to the mold cavity via each sprue.

United States Patent Posner 1 Feb. 15, 1972 [54] MOLD FOR MOLDINGARTICLES COMPOSED OF DIFFERENT MATERIALS [72] Inventor: Richard Posner,East Northport, N.Y.

[73] Assignee: Creative Polymer Products Corp., Long Island City, NY.

221 Filed: Mar. 12, 1970 211 Appl. No.: 18,946

2,962,761 12/1960 HObSOn ..18/42 1) ux 2,799,435 7/1957 Abplanap.........l8/42 D x 2,878,517 3/1959 cram/61.... ..249/107 3,259,356 7/1966116111 1 8/30 uc x 3,319,300 /1967 116111 ..18/30 UC x FOREIGN PATENTSOR APPLICATIONS 759,666 10/1956 01661131116111 ..18/42 D 6,709,8171/1968 N8tl'lellandS....

ltaly ..18/30 uc OTHER PUBLICATIONS Modern Plastics Encyclopediaarticle; September 1965: pp. 725,726

lnjection-Mould Design Fundamentals article; pp. 98: The IndustrialPress N.Y., NY.

Primary ExaminerJ Howard Flint, Jr. Att0rneyl-lane, Baxley & Spiecens [57] ABSTRACT A mold has at least one mold cavity and two mutuallyisolated sprues. Each sprue is connected via a different runner or gateto the mold cavity. A different material is fed to the mold cavity viaeach sprue.

5C|aims,5Drawing Figures PATENTEDFEB 15 I872 FIG.2

INVENTOR.

BY Richard Posner le/m,

ATTORNEY MOLD FOR MOLDING ARTICLES COMPOSED OF DIFFERENT MATERIALS Thisinvention pertains to molds and, more particularly, to molds for moldingarticles from a settable fluid composed of at least two differentmaterials.

Quite often in molding articles such as costume jewelry stones, giftwareand household decorations, marbelized effects are desired. In suchcases, it is necessary to combine two different colored resins or thelike in a partially mixed state in a mold cavity. Heretofore, when thiswas attempted very indesirable marbelized effects were obtained becauseof the difficulty in controlling the combination. In other cases, it maybe necessary to use very rapidly setting resins. However, the nature ofthe mold may be such that the time between the mixing of the resin andthe catalyst and the entry of the resin and catalyst into the moldcavity is long enough to cause setting of the mixture in the runner orgate before the cavity is filled.

In either case, it highly desirable to mix the two materials only attheir entry into the mold cavity.

It is, accordingly, a general object of the invention to provide animproved mold for molding articles from a settable fluid composed of atleast two different materials.

It is another object of the invention to provide such a mold wherein thetwo different materials are only mixed at their point of entry into themold cavity.

Briefly, the invention contemplates a mold for molding articles from asettable fluid composed of at least two different materials. The moldcomprises at least two mold sections in abutting relationship. The moldsections have at least one mold cavity defining the form ofthe articleto be molded.

In at least one of the mold sections there are two mutually isolatedsprues. Each sprue receives a different one of the materials. Adifferent runner connects each sprue to the mold cavity so that thematerials received by each of the sprues only combine as they enter thecavity.

A feature of the invention is to make such a mold rotatable with centralsprues so that centrifugal force may be utilized in filling the moldcavity with a bubble-free material.

A further feature of the invention is to include other mold cavities fedfrom only one of the sprues so that solid color as well as marbelizedarticles can be simultaneously molded.

Other objects, features and advantages of the invention will be apparentfrom the following detailed description when read with the accompanyingdrawing which shows the presently contemplated preferred embodiment ofthe invention.

In the drawing:

FIG. I is a schematic diagram of a mold being fed with two differentmaterials in accordance with the invention;

FIG. 2 shows a top view of the mold of FIG. 1 with a portion of the topmold section broken away;

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a top view of the central inset defining the sprues of themold of FIG. 2; and

FIG. 5 is a cross-sectional view taken along the line 5-5 of FIG. 4.

In FIG. 1, a mold comprising mold sections 10A and 10B is rotatablydriven by motor M while being simultaneously fed different-coloredsettable resins from reservoirs A and B. As will hereinafter becomeapparent, the mold will simultaneously produce articles bearing thecolor of the resin in reservoir A, articles bearing the color of theresin in reservoir B and articles that are marbelized with the twocolors.

The actual construction of mold I0 is shown in FIGS. 2 to 5. The mold 10includes top mold section 10A, bottom mold section 108 andsprue-defining inset 12 along the axis of rotation of the mold 10. Topmold section 10A is annular with a central opening 14 through whichinsert 12 is placed to rest on bottom mold section 10B. Alignment bossesand mating recesses are provided to line up the sections and insert.Within the mold sections 10A and 10B and radially displaced from theaxis of rotation are mold cavities 16, 18 and 20.

Within the center of insert 12 is a central sprue 24. Annularly disposedabout central sprue 24 and concentric therewith is a second sprue 26.Sprue 26 is defined by the periphery of central opening 14 and the outerwall 28 of insert 12. As can be seen, reservoir A feeds central sprue 24and reservoir B feeds second sprue 26.

Cut in mold section 10B is a runner or gate 30 which connects secondsprue 26 to cavity 16, as well as runners 32 and 34 which connectcentral sprue 24 to cavity 16. Runners 30, 32 and 34 meet at region 36adjacent the mold cavity 16. Runner 30 continues as runner 30A in insert12 Thus, when reservoirs A and B simultaneously deliver their differentcolored resins, marbelized mixing takes place at region 36 and amarbelized mixture is fed into mold cavity 16.

In addition, only a single runner 38 in mold section 10B connects sprue26 to mold section 18. Therefore, the article molded in cavity 18 willbe the color of the material from reservoir B. Finally, a single runner40 connects central sprue 24 to mold cavity 20 via runner 40A in insert12. Therefore, the article molded in cavity 20 will have the color ofthe resin from reservoir A.

There has thus been shown mold for molding marbelized articles as wellas solid-colored articles at the same time. While the example givenshows the use of different-colored resins, it should be realized thatwith respect to mold cavity 16 (assuming cavities 18 and 20 are notpresent) the fluid from the reservoirs could be a resin and a catalystwith the mixing occurring at the inlet to the cavity.

While only one embodiment of the invention has been shown and describedin detail, there will now be obvious to those skilled in the art, manymodifications and variations satisfying many or all of the objects ofthe invention without departing from the spirit thereof as defined bythe appended claims.

What is claimed is:

1. A mold for molding articles from a settable fluid composed of atleast two different materials comprising at least two mold sections inabutting relationship, said mold sections being provided with at leastone mold cavity defining the form of the article to be molded, at leastfirst and second mutually isolated sprues, in at least one of said moldsections, each of said sprues being adapted to receive a different oneof the materials, a first gate in at least one of said mold sectionsconductively connecting said first sprue to a given entrance port ofsaid mold cavity, and a second gate in at least one of said moldsections conductively connecting said second sprue to said givenentrance port of said mold cavity thereby said different materials mixat the entrance of said mold cavity.

2. The mold of claim I wherein said mold sections are rotatable about agiven axis of rotation, said mold cavity is radially displaced from saidaxis of rotation, said first sprue is aligned with said axis ofrotation, and said second sprue is annular in shape and concentricallydisposed about said first sprue.

3. The mold of claim 1 further comprising a second mold cavity in saidmold sections and a third gate connecting one of said sprues to saidsecond mold cavity.

4. A mold for molding articles from a settable fluid composed of atleast two different materials comprising at least two mold sections inabutting relationship, said mold sections being rotatable about a givenaxis of rotation, said mold sections being provided with at least firstand second mold cavities defining the forms of the articles to bemolded, said mold cavities being radially displaced from said axis ofrotation, at least first and second mutually isolated sprues, in atleast one of said mold sections, each of said sprues being adapted toreceive a different one of the materials, a first gate in at least oneof said mold sections conductively connecting said first sprue to saidfirst mold cavity, a second gate in at least one of said mold sectionsconductively connecting said second sprue to said first mold cavity, anda third gate connecting one of said sprues to said second mold cavity,said first sprue being aligned with said axis of rotation, and saidsecond sprue being annular in shape and concentrically disposed aboutsaid first sprue.

5. The mold of claim 4 further comprising a third mold cavity in saidmold sections and a fourth gate connecting the other of said sprues tosaid third mold cavity. 5

1. A mold for molding articles from a settable fluid composed of atleast two different materials comprising at least two mold sections inabutting relationship, said mold sections being provided with at leastone mold cavity defining the form of the article to be molded, at leastfirst and second mutually isolated sprues, in at least one of said moldsections, each of said sprues being adapted to receive a different oneof the materials, a first gate in at least one of said mold sectionsconductively connecting said first sprue to a given entrance port ofsaid mold cavity, and a second gate in at least one of said moldsections conductively connecting said second sprue to said givenentrance port of said mold cavity thereby said different materials mixat the entrance of said mold cavity.
 2. The mold of claim 1 wherein saidmold sections are rotatable about a given axis of rotation, said moldcavity is radially displaced from said axis of rotation, said firstsprue is aligned with said axis of rotation, and said second sprue isannular in shape and concentrically disposed about said first sprue. 3.The mold of claim 1 further comprising a second mold cavity in said moldsections and a third gate connecting one of said sprues to said secondmold cavity.
 4. A mold for molding articles from a settable fluidcomposed of at least two different materials comprising at least twomold sections in abutting relationship, said mold sections beingrotatable about a given axis of rotation, said mold sections beingprovided with at least first and second mold cavities defining the formsof the articles to be molded, said mold cavities being radiallydisplaced from said axis of rotation, at least first and second mutuallyisolated sprues, in at least one of said mold sections, each of saidsprues being adapted to receive a different one of the materials, afirst gate in at least one of said mold sections conductively connectingsaid first sprue to said first mold cavity, a second gate in at leastone of said mold sections conductively connecting said second sprue tosaid first mold cavity, and a third gate connecting one of said spruesto said second mold cavity, said first sprue being aligned with saidaxis of rotation, and said second sprue being annular in shape andconcentrically disposed about said first sprue.
 5. The mold of claim 4further comprising a third mold cavity in said mold sections and afourth gate connecting the other of said sprues to said third moldcavity.